Pollination involves a series of interactions between the surface of the male gametophyte and the extracellular matrix of several distinct sporophytic tissues in the pistil. Pollen germinates on the stigmatic surface and develops a tube that elongates in the transmitting tract of the style to transport the male gametes to the embryo sac inside the ovary. Pollen tube growth is fuelled by cytosolic activities within the pollen, but female tissues facilitate this process to ensure that pollen tubes arrive at the ovary when the ovules are the most receptive for maximum reproductive success. interactions between pollen and pistil factors. probably both physical and biochemical. must be transmitted to the pollen cytosol to elicit the appropriate pollen cellular activities. Our research focuses on identifying the molecules that are involved in these interactions, understanding their biochemical and cellular bases, transmittal of these interactive signals into the pollen cytosol and the pollen cellular responses. (C) 2000 Annals of Botany Company.